1. Field of the Invention
The present invention relates to a surface light source device and a liquid crystal display (LCD) device having the surface light source device. More particularly, the present invention relates to a surface light source device capable of supplying a surface light to a liquid crystal display panel to display images, and an LCD device having the surface light source device.
2. Description of the Related Art
There are a variety of flat panel devices and a liquid crystal display (LCD) device represents one such type of flat panel display device. The LCD device displays images using liquid crystal. The LCD device has various merits, such as, for example, thin thickness, light weight, low driving voltage, low power consumption, etc. Therefore, the LCD device has been used in various fields.
The LCD device is a non-emissive type display device so that the LCD device includes a backlight assembly to provide light.
In general, the backlight assembly employs a cold cathode fluorescent lamp (CCFL) as a light source. As the LCD device becomes large in size, the number of CCFLs required for the LCD device increases. As LCD devices increase in size, manufacturing costs are also increased and optical properties such as luminance uniformity will decrease, that is, become deteriorated.
A surface light source device has been developed to solve the above-mentioned problems. The surface light source device includes a lamp body having a plurality of discharge spaces and external electrodes for applying a discharge voltage to the lamp body.
When an inverter applies the discharge voltage to the external electrodes of the surface light source device, the surface light source device generates ultraviolet light through a discharge gas in each of the discharge spaces. The ultraviolet light is converted into visible light through a fluorescent layer formed on an inner surface of the lamp body.
When the surface light source device is operated only through the external electrodes, the associated light emitting efficiency is lowered. Therefore, a surface light source device that further includes hollow electrodes disposed in the lamp body has been developed in order to enhance the light emitting efficiency.
The surface light source device having the hollow electrodes has a relatively higher light emitting efficiency than the conventional surface light source device, but ions that are accelerated by the discharge voltage collide with the hollow electrodes. Therefore, the life span of the hollow electrodes is decreased and a portion of an electrode is blackened.